Is BuddyPress a good alternative to Elgg?

Last May, when I was young and inexperienced in the ways of social networking software, I started up a social networking site for homeschooled teens, using Elgg social networking software. Elgg worked out well for several months, but in the last month I’ve absolutely come to my wits’ end with it. Don’t get me wrong, it’s a nice software. However, it’s just too hard on server resources and is using way too much of my limited spare time. After my Elgg site started repeatedly crashing due to overusing the maximum amount of MySQL connections alloted to me, I found out that I either have to switch to a different software, or purchase the $70 a month ‘VPS Pro’ hosting from my webhost. As you can probably imagine, a social networking site for homeschooled teens simply does not make enough money to justify a $70 a month hosting bill. For those reasons, I’m considering switching over to a software that’s not quite as labour-intensive/hard on the server. BuddyPress seems to meet these requirements, but I have a few questions before I can decide whether or not to use it.

First of all (and this is the question I wish I’d asked when I started with Elgg), would BuddyPress/Wordpress require VPS hosting, with only about 150 members in all and generally a maximum of five (though usually more like zero to two) users online at any given time? (Of course, I won’t mind upgrading to better hosting when my site gets larger, but for now I can only afford about $25 a month, maximum.)

Second, is there any simple way someone who’s not terribly skilled at PHP or MySQL (like myself) could import user data (i.e. member login data, blog posts, groups) from Elgg to BuddyPress? This isn’t extremely important to me, as my site members should be alright with moving their accounts over to a new site by themselves, but it would be nice if this were possible.

Lastly, is it difficult to learn how to make plugins and themes for BuddyPress? Would the documentation be very hard for someone who’s just a bit more than a beginner with PHP and MySQL to understand?

Thanks in advance for your help! I’m really liking the look of BuddyPress, and I hope it ends up working out for me!